The present invention is directed to a manually held and operated toothbrush or to a powered toothbrush which includes a handle and a head. Cleaning elements are mounted to the head such as tufts of bristles. When toothpaste is applied to the cleaning elements the user inserts the head into the mouth and brushes the teeth in a known manner.
The head of a conventional toothbrush usually has a flat or slightly altered surface to which cleaning elements are attached. Usually the cleaning elements are strands of plastic material(s) formed into tufts or other groupings. The strand groupings are attached to the head either before or after forming the toothbrush handle.
Various attempts have been made for providing flexibility to the manner in which the bristles are attached. Various approaches have also been taken wherein the bristle carrying surface of the head is not flat. U.S. Pat. No. 1,688,581, for example, discloses a toothbrush having a bristle carrying member which is ordinarily bowed inwardly into the hollow head. The bristle carrying member can be bowed outwardly by manipulating a wire mounted in the toothbrush.
U.S. Pat. No. 5,483,722 discloses a toothbrush with a resilient flexible bristle support which spans spaced parallel handle extensions. Different embodiments of the toothbrush include having the support bowed inwardly or bowed outwardly.
U.S. Pat. No. 5,325,560 relates to an orthodontic toothbrush which includes various rows of bristles including centrally located longitudinally arranged sets of bristles mounted on a flexible member over an air pocket.
U.S. Pat. No. 5,799,354 discloses a toothbrush of rocker formation wherein base sections are joined together by hinges. The toothbrush also includes a hollow space below the base sections.
U.S. Pat. No. 5,454,133 discloses a toothbrush having a closed system of passageways for a non-compressible medium such as a compressed gas which flows below the bristle carrying base members.
U.S. Pat. No. 6,088,870 discloses a toothbrush head with flexibly mounted bristles by utilizing a flexibly resilient lattice network so that the bristles deflect during brushing to conform to various arcuate surfaces of the teeth.
U.S. Pat. No. 2,003,243 issued May 28, 1935 to Campbell et al. discloses blocks containing groups of bristles that are mounted on a flexible wire attached to a rigid toothbrush head (page 1, column 2, lines 45-55). The flexibility of this mounting wire helps the bristles to conform to the shape of teeth being cleaned.
Blakeman U.S. Pat. No. 2,706,825 issued Apr. 26, 1955 discloses a demountable bristle holder for a toothbrush which flexes up and down relative to the longitudinal axis of the toothbrush body. This flexible member changes position. This plus the pressure of the brush against teeth and movement of the brush permits the brush to contact the teeth at various degrees of conformation (column 2, lines 15-18).
Peters U.S. Pat. No. 4,520,526 issued Jun. 4, 1985 has a flexible section in the handle which permits the head portion to move relative to the handle portion of the toothbrush in one plane. This patent suggests that the flexibility avoids damaging delicate tooth material and gum tissue (column 1, line 42-44). Similar structures for imparting flexibility to the head of a toothbrush and thereby reduce wear on tooth and gum are disclosed in U.S. Pat. No. 5,146,645.
Other approaches to flexible mounting of toothbrush cleaning elements are disclosed in U.S. Pat. Nos. 3,355,546 and 5,839,149. In these patents, the head of the toothbrush is placed under the biting surface of the tooth in a plane perpendicular to the plane of the tooth. The head of the brush when so oriented has short bristles in the middle of the head which are pushed against the biting surface which causes longer outer bristles to rotate into engagement with the side of the teeth and the gum line.
U.S. Pat. No. 5,987,690 issued Nov. 23, 1999 to Heuler discloses a toothbrush with linkages between handle and head that facilitate deflection of the head so that the free bristle ends retain parallel alignment with respect to the handle during use.
U.S. Pat. No. 6,003,189 issued Dec. 21, 1999 discloses a flexible section of a toothbrush between handle and head to absorb part of the force applied by the user of a toothbrush. An elastic shock absorbing means is inserted in this section to bias the head into its inoperative position.
U.S. Pat. No. 6,141,817 discloses a toothbrush head with a central longitudinal axis that underlies the middle of a resilient member containing bristles. The central axis limits deformation of the middle of the resilient member. The balance of the head on either side of the central axis is sloped to allow greater movement of the flexible member, thereby causing outer bristles to splay outward. The outward spraying is believed to improve crevice intrusion of the bristles (column 2, lines 40-46).
European Patent Publication 0 454 625 A1 dated Oct. 30, 1991 discloses a cam in the handle of a tooth-brush that can be used to change the angular orientation of the head relative to the handle.
Other attempts made in the prior art to provide some form of movability of cleaning elements are described in U.S. Pat. No. 5,228,466 and WO 90/01281 which disclose a toothbrush wherein both the handle and head are longitudinally hinged so as to provide displaceable bristles which are straddled about a row of teeth.
U.S. Pat. No. 1,616,484 discloses a toothbrush which is hinged along the length of the handle so that two spaced head sections can be disposed back to back with respect to each other. U.S. Pat. No. 1,616,484 discloses a hinged toothbrush that would provide for brushing a tooth from three different directions. U.S. Pat. Nos. 5,528,782 and 5,269,083 disclose the bristles as being mounted in a rocking manner. U.S. Pat. No. 5,799,354 discloses the utilization of a hollow space to provide for a hinging action. U.S. Pat. No. 1,924,152 discloses a toothbrush having rows of rubber bristles. U.S. Pat. No. 301,644 discloses a toothbrush having rows of bristles mounted in rubber tongues.
U.S. Pat. No. Des. 421,843 illustrates a toothbrush wherein the bristle carrying surfaces appears to be non-planar.
U.S. Pat. No. 4,240,452 discloses an elastic base toothbrush wherein a bristle carrying plate is mounted over rubber tubes.
A number of patents disclose some tooth and/or gum massage devices having non-planar surfaces. For example, British Patent No. 524135 relates to a gum massaging device having an air filled hollow rubber head to provide an air cushion for the gum massaging members. U.S. Pat. No. 1,058,273 discloses a massaging device having an interior air space. U.S. Pat. No. 2,148,483 discloses a tooth and gum massager and exerciser which includes a void filled with air. U.S. Pat. No. 2,176,309 also discloses a gum massager having air pockets.
Hairbrushes are also disclosed in various patents having dome shaped outer surfaces. Examples of these patents include U.S. Pat. Nos. 3,739,419, 4,500,939 and 5,581,840. Similarly U.S. Pat. No. Des. 892,299 shows a toilet brush with a convex shaped bristle carrying surface.